Refrigerator for solid co



Patented Jan. 8, 1 935 UNITED STATES PATENT OFFICE John H. Wooll, San Francisco, Calif.

Application April 15, 1932, Serial No. 605,541

' Renewed May 19, 1934 2 Claims. (01. 62 -91.5)

This invention is concerned with the use of solid CO2 as a refrigerant and it is generally the object of my invention to provide means enabling this extremely low temperature material to be used in 5 maintaining a refrigerating temperature.

It is known that solid carbon dioxide sublimes at a temperature of minus 110 F. If this material is placed in contact with, or in close proximity to, a material to be cooled, or maintained cold, the material will usually freeze and become extremely hard. This is undesirable since the material must be thawed outbefore it can be cut or eaten with ease. The present invention enables such an extremely low temperature refrigerant to be used successfully without freezing materials to be refrigerated. Thus, I am able to use solid carbon dioxide to maintain a refrigerating temperature and to vary that temperature. I have successfully maintained a refrigerating temperature in the range of to 50 F. and have varied this temperature practically at will. The consumption of refrigerant has been very low and on a cost basis, the cost of refrigeration is lower than the cost when using ice or mechanical a installations.

This invention is also concerned with the inanner in which the low temperature refrigerant is stored or packaged in the refrigerator. Thus,- I have found that by packing the solid CO: in a certain manner, it remains much longer as an effective refrigerant, its effectiveness is at a maximum while freezing of the material is obviated.

The inventionupossesses other objects and features of advantage, some'of which, with the fore- I) going, will appear at length in the following specification. In the drawing forming a part of the specification, I have disclosed certain present preferred means for practising my invention. It is of course to be borne in mind that other forms may be adopted for embodying my invention, within the scope of the claims.

In said drawing:-

Figure 1 is a section through a refrigerator embodying my invention.

45 Figure 2 is a sectional view showing the arrangement of a device for packing the solid CO2 for refrigerating.

In the device shown in Figure 1, a refrigerator 6 is provided with a removable cover 7 for an opening in a side of the box 6. The box 6 is made of a metal exterior shell 8 and a metal or porcelain shell 9 arranged on insulating material as cork 11 in shell 8. Any desired refrigerator construction can of course be employed for box 6.

Removable cover 7 is secured to box 6 by hinge l2 and rivets 13. The cover 7 has a tapered portion 14 engaging a similarly shaped portion on the box so that the cover, when lowered into place, fits snugly to close the box. Cover 7 includes a container 16, usually of metal or porcelain, de-

pending therefrom into box 6. In accordance with this invention, container 16 is linedwith a fibrous or spongy material 17 such as felt, matted hair or flannel. This material is wetted with water, a brine or other liquid that will be frozen by a block 18 of solid CO: placed in container 16. The lining of felt can be removed easily and different thicknesses utilized to secure different temperatures in box 6. Thus, a separate disc 19 of wet felt inserted on the bottom of the felt liner 17 raises the temperature in the box by F. while a thicker felt liner raises the temperature in the box 6 even more so that the contents thereof are kept at a higher refrigerating temperature.

It is to be noted that the solid C02 container 16 is heavily insulated except where the container depends into box 6. This makes the absorption of heat from container 6 preferential to absorption from any other point and the efi'ort of the refrigeiant is devoted to maintaining the box 6 and its contents cool. The metal or porcelain shells are discontinued so that only insulating material extends from theatmosphere to the interior of the box or the container 16.

This prevents heat from creeping along the metal or porcelain skin and so destroying the efliciency of the refrigerator; the engaging faces of tapered portions 14 and 22' are of insulating material.

The evolution of CO2 vapor from the solid is held back by providing lid 21 for cover 7 and container 16. Lid 21 includes tapered portion 22 depending to engage cover 7 and seal the CO2 in the container. Screws 23 engage cover 7 to hold lid 21 in sealing engagement with cover 7 to prevent escape of CO2 vapor. Gasket 24 is placed between lid 21 and cover 7 to seal ofl. vapor escape after portion 22 of lid 21 has seated on the cover. The engagement of tapered portion 22 with cover 7 and the fit of gasket 24 are such that free CO2 vapor escape is prohibited and a pressure is maintained on the CO2 block. This pressure is not great since gasket 24 and tapered portion 22 do not provide an absolute seal. However, they can be made to provide a closed container from which pressure is released by a pressure valve. The cover and lid form a unitary structure that can be moved about hinge 12 by knob 26.

The refrigerator shown in Figure 1 has proven very economical in handling commodities as ice cream and other frozen or chilled foods, as confections, cocktails. etc. A relatively inexpensive .box which can be kept economically at a refrigerating temperature is available. It is quickly responsive to the presence of a hot body in the box, container 16 being made of a goodheat conductor quickly attempts to raise in temperature with the result that the heat is absorbed by the frozen mass of wet fibrous material and the container 16 cooled. The wet fibrous material provides in effect a block of ice about the CO2 block with the advantage that its effect can be controlled by varying the thickness of the material, by wetting the material to various degrees of saturation and by wetting the material with different liquids; mass insulates to prevent the CO2 from cooling the box too low and yet conducts cold to the box sufiicient to keep the box at a refrigerating temperature.

The wet fibrous material can also be used to line or cover a water or other liquid shield for the CO2 block as I have disclosed in my application, Serial No. 491,671, filed Oct. 28, 1930.

In Figure 2, I have disclosed another use of the present invention, particularly as applied to commodities which are preserved by placing the refrigerant directly in contact with the materiaL- Thus fish are often packed with ice in a box. If solid CO2 is used, the fish become frozen. By means of my invention, solid CO2 can be used in place of ice, to secure the same refrigerating effect as if ice were used with all the advantages of solid CO2. Thus, I preferably place a block 41 of solid CO2 in a blanket or bag 42 of fibrous material, such as felt; The material is wet with water, brine or other liquid so that it freezes. The refrigerating effect of the CO2 is cut down to that of ice or the cooled brine or liquid used and the fish or other commodity is lowered approximately to that temperature and not to that of. the solid CO2, minus 110 F.

To prevent mechanical disintegration of the solid CO2 I preferably protect it by placing it in a wire cage 43. The wet bag 42 of fibrous material is placed about the cage and the solid CO2 soon freezes the wet bag. Vapor evolution from the solid CO2 is cut down since the CO2 is, in effect, encased in a block of ice.

The frozen mass of wet fibrous.

' This feature is claimed in my continuing and copending case Serial Number 686,024 filed August 21, 1933.

I claim: I

1. In combination, a receptacle having a space for products to be refrigerated and including walls of heat insulating materials, a container partially encased by and extending from one of said walls with the closed end of said receptacle in said spaceto position a quantity of solid carbon dioxide in heat exchange relationship with said space, and a fibrous lining for said container wetted so as to be frozen by said solid carbon dioxide and thereby impregnated with ice to control heat removal from said space.

2. In combination, a receptacle having a space for products to be refrigerated and including a wall of heat insulating material, a container extending through said wall and partially encased thereby with the closed end thereof in said space to position a charge of solid carbon dioxide in heat absorbing relationship to said space, a cover for said container, and a wall of fibrous material interposed between said charge of solid carbon dioxide in said container and said space to control heat removal therefrom.

3. In combination, a receptacle having a space for products to be refrigerated and an opening into said space, a closure for said opening, said closure including a container extending into said space to position a refrigerant as solid carbon dioxide in only heat exchange relationship with said space, a wall of wet, fibrous material interposed between said carbon dioxide and said space, said wet material being frozen by said refrigerant whereby said material is impregnated with ice, and a closure for said container.

J OHN H. WOOLL. 

